Shaft furnaces



Filed Feb. 2l. 1964 July 26, 1966 /N VEN TOR LW ---l 6. 5 5 5. -www mwum.. 7 4

United States Patent O 3,262,687 SHAFT FURNACES Manfred Freygang, Moers,Germany, assignor to Phoenix- 4 Crarms. (cl. 263-29) The bases of shaftfurnaces such as blast furnaces and cupola furnaces are made of carbonor refractory bricks the sides of which are tapered and which are builtup after the fashion of inverted arches that are braced by the furnaceshaft or hearth masonry. Conventionally, the base is erected inlayers-ie., in the form of three or four layers of bricks placedhorizontally-with the gaps between adjacent bricks in any one layeroiset from the similar gaps in the layer immediately above or below. Theassumption has been that the main reason for the base Wearing is liquidmetal penetrating into the gaps between the bricks, and so it has beenthought advisable to provide a very frequent interruption of thedownwardly extending gaps. A disadvantage of this kind of lining,however, is that the failure of a single brick nulliiies the wedgingaction which keeps all the bricks together, with the result that, sincethe bricks forming the layer are of low density, the whole layer ofbricks rises to the surface of the iron melt and is scoriiied.

In accordance with the present invention, the base of a shaft furnace isformed by a layer of a number of elongated refractory bricks on end, thebricks at the edge of the base being located in position and the otherbricks tapering in the upward direction so that they are keyed inposition against upward movement by their engagement with one another.In this single layer of tapered bricks the gaps between adjacent bricksbecome so long that even after considerable wear, extending possiblyover a period of many years, there is little chance of penetrationthrough the gaps to undermine the base and make it rise to the surfaceof the iron.

The said layer of tapered bricks forming the essential part of the basemay be erected on a comparatively thin base layer of bricks the gapsbetween which are offset from the gaps between the upright bricks.

Preferably, the vertical construction of the upright base bricks extendsas far as the lining of the furnace casing or jacket. The bottom of thejacket lining may be formed by edge bricks which are also elongated andare positioned on edge but are shorter than the rest of the bricksforming the base. There is then an interruption in the horizontal jointat the edge of the top of the base bricks.

Preferably the bricks are arranged in parallel rows and -taper onlyalong their surfaces which are adjacent bricks in the same row, theadjacent faces of one pair of adjacent bricks in each row being normalto the flat top of the base.l

One example of a blast furnace base constructed in accordance with theinvention is illustrated in the accompanying drawings, in which:

FIGURE 1 is a section through the hearth portion of a blast furnacetaken along a vertical plane, and

FIGURE 2 is a sectional view according to line 2 2 in FIG. l.

The blast furnace hearth portion shown in the drawing comprises in theconventional manner an outer shell of metal consisting of a partlycylindrical and partly conical side portion 1 and a base portion 2. Thisshell i-s provided with a lining of refractory material, said materialconsisting of bricks. These bricks are preferably made of carbon, butthey may also consist of any other refractory material used heretoforein furnaces of the kind under discussion. The lining covers the baseportion 2 of the shell as well as its side portion 1.

3,262,687 Patented July 25, 1966 In the example shown in the drawing,the part of the lining covering the base portion 2 of the Shell consistsof a lower and rather thin layer of bricks 3 having the shape ofrectangular blocks. A second layer of bricks is disposed above thebottom layer, the second layer consisting of rather tall bricks 4, 5 and6, bricks 4 being disposed adjacent the outer shell and bricks 5 and 6filling the space between bricks 4. The shape of bricks 5 and 6 is suchthat it tapers from the bottom to the top. In other words, any suchbrick has a bottom face of rectangular shape, a top face of rectangularshape, two opposite side faces of rectangular shape and two oppositeside faces of trapezoidal shape. Thus, in one dimension, the rectangleforming the top falce becomes slightly smaller than the rectangleforming the bottom face. Bricks 4 may have any suitable shape, forexample that of a parallelepiped, as shown in the drawing. I

It should be noted that there is a gap 7 between bricks 4 and theadjoining outer shell, this gap having a Width of for example 2 to 4inches and being filled with mortar.

While the lower layer of bricks 3 is of rather small height, the bricks4, 5 and 6 in the upper layer may have a height of 60 to 100 inches oreven more and thus are several times as high as any one of the layersused in conventional furnaces.

The part of the refractory lining covering ythe base portion 1 of theshell consist of two vertical layers of bricks 8 and 9, extending acrosspart of the hearth portion of the furnace, and a single vertical layer10 of bricks forming the upper continuation of layers 8 and 9. It willbe noted that the bricks 4 are slightly less high than all the otherbricks of the same layer, so that the lowermost bricks 8 of the sidelining are offset against the plane formed by the entirety of the topfaces of bricks 5 and 6, said plane being designated 11 in FIG. 1.

The procedure in providing the shell of a furnace with a refractorylining of the type shown in the drawing is as follows:

First, the layer of bricks 3 is placed on the bottom portion 2 of theshell in the usual manner. The surfaces of the bricks may be coveredwith a film of refractory sealing material, such as is obtained from asuspension of powdered carbon in water, which suspension fills the y arethen added until the row is completed, with the exception, however, ofthe respective bricks 4 and 6 a't either end of the row. Bricks 4 arethen inserted and at rst pushed against the outer shell. This leavessufficient space to introduce bricks 6, despite their tapered shape.With all the bricks of one row having been brought in position, bricks 4are shifted inwardly to contact the adjacent bricks 6 and at the sametime forming the gaps 7 which thereupon are lled with mortar.

With all the rows of bricks having been positioned in the way described,the bottom lining is completed and the side lining, consisting of bricklayers 8, 9 and 10, may then be built in the usual way.

The bricks 4, 5 and 6 forming the major part of the bottom layer mayalso be covered with .a refractory sealing film of the aforementionednature to fill the gaps between adjacent bricks and between the upperand lower layers.

Bricks 4, 5 and 6 are so disposed on the bricks 3 of the lower layerthat their joints are olfse-t from the joints of the bricks in the lowerlayer, as shown in the drawing.

I claim:

1. Shaft furnace comprising an outer steel jacket and an innerrefractory lining forming a hearth for the furnace, said liningincluding a bottom and a side portion, said bottom lportion comprising aVrelatively narrow foundation layer of bricks and a main base layerformed by a plurality of elongated bricks horizont-ally aligned insubstantially parallel rows and superimposed on said foundation layer,said elongated Ibricks having a length in the vertical direction manytimes greater than the thickness of said foundation layer, the elongatedbricks at the ends of =asid rows being shorter in the vertical directionlthan the elongated bricks elongated intermediatevthereto, and saidintermediate bricks being tapered upwardly in the vertical direction andbeing in engagement with one another so that said intermediate elongatedbricks are wedged in position `against upward displacement thereof.

2. Shaft furnace comprising an outer steel jacket and an innerrefractory lining forming a hearth for the furnace, said liningincluding a bottom and a side portion, said bottom portion comprising arelatively narrow foundation layer of .bricks and a relatively wide mainlayer formed by a plurality of elongated bricks horizontally aligned insubstantially parallel rows 4and superimposed on said foundation layer,said elongated bricks having a length in the vertical direction of from60 to 100 inches, the elongated bricks at the ends of said rows beingshorter in the vertical direction rthan the elongated bricksintermediate thereto, and said intermediate elongated bricks beingtapered upwardly lin the vertical direction and being in engagement withone another so that said intermediate elongated bricks are wedged inposition against upward displacement thereof.

3. Shaft furnace according to claim 1 wherein each of the elongatedbricks intermediate the end bricks 4of said rows has a bottomrectangular face, a top rectangular face, a pair of opposite rectangularside faces Iand a pair of opposite trapezoidal side faces.

4. A furnace according to claim 1, in which the elongated bricks aremade of carbon.

References Cited by the Examiner JOHN I. CAMBY, Acting Primary Examiner.

Keydel 26346 X

1. SHAFT FURNACE COMPRISING AN OUTER STEEL JACKET AND AN INNERREFRACTORY LINING FORMING A HEARTH FOR THE FURNACE, SAID LININGINCLUDING A BOTTOM AND A SIDE PORTION, SAID BOTTOM PORTION COMPRISING ARELATIVELY NARROW FOUNDATION LAYER OF BRICKS AND A MINA BASE LAYERFORMED BY A PLURALITY OF ELONGATED BRICKS HORIZONTALLY ALIGNED INSUBSTANTIALLY PARALLEL ROWS AND SUPERIMPOSED ON SAID FOUNDATION LAYER,SAID ELONGATED BRICKS HAVING A LENGTH IN THE VERTICAL DIRECTION MANYTIMES GREATER THAN THE THICKNESS OF SAID FOUNDATION LAYER, THE ELONGATEDBRICKES AT THE ENDS OF SAID ROWS BEING SHORTER IN THE VERTICAL DIRECTIONTHAN THE ELONGATED BRICKS ELONGATED INTERMEDIATE THERETO, AND SAIDINTERMEDIATE BRICKS BEING TAPERED UPWARDLY IN THE VERTICAL DIRECTION ANDBEING IN ENGAGEMENT WITH ONE ANOTHER SO THAT SAID INTERMEDIATE ELONGATEDBRICKS ARE WEDGED IN POSITION AGAINST UPWARD DISPLACEMENT THEREOF.